A basis for a coherent derating approach, which is founded on principal parameters from commonly referred to derating procedures, is discussed. A weighting technique may couple the diminishing drag influences to rheological effects for the intermediate two-component and viscous area here represented by highly concentrated mine tailings slurries. Loop test results with authentic tailings demonstrated the decreasing head derating with increased rotary speed and thus the viscous influence, a dependence which increased with particle fineness. A marked effect on the derating with yield stresses of 200-260 Pa was also found. Maximum reductions in head and efficiency were 15 and 25%, respectively, at solids concentrations by volume of up to about 50%.
展开▼
